Gemfile fix
Gemfile fix

Signed-off-by: Jeroen van Baarsen <2e488d5cebaf6d2832884be70e328933bd4c80ab@gmail.com>

8thcolor/eurucamp2014-htdsadr,8thcolor/rubyconfau2015-sadr,8thcolor/rubyconfau2015-sadr,8thcolor/rubyconfau2015-sadr,8thcolor/eurucamp2014-htdsadr,8thcolor/eurucamp2014-htdsadr